Annual report pursuant to Section 13 and 15(d)

Stock Plans and Management Compensation (Details 1)

v3.8.0.1
Stock Plans and Management Compensation (Details 1) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Shares Available for Grant (in shares) 5,400    
Non-Vested Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Awards Vesting Period (in years) 3 years    
Age of Grantee 62 years    
Share-Based Compensation Expense $ 11,100 $ 10,100 $ 12,900
Share-Based Compensation Expense, Tax Benefit 4,200 3,900 4,900
Fair Value of Shares Vested During the Period $ 12,100 $ 13,800 $ 20,400
Weighted Average Grant Date Fair Value $ 51.69 $ 43.35  
Awarded - Weighted Average Grant Date Fair Value 60.30 $ 40.01 $ 53.77
Forfeited - Weighted Average Grant Date Fair Value 50.19    
Vested - Weighted Average Grant Date Fair Value $ 46.48    
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Outstanding at January 1 379    
Awarded 240    
Forfeited (25)    
Vested (218)    
Outstanding at December 31 376 379  
Unrecognized Compensation Cost $ 7,400    
Unrecognized Compensation Cost, Period for Recognition 1 year 3 months 18 days    
Non-Vested Stock Awards [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Age of Grantee plus Grantees Total Number of Years of Service 70    
Stock Options and SAR's [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Awards Vesting Period (in years) 4 years    
Age of Grantee 62 years    
SARs/Stock Options Outstanding [Roll Forward]      
Outstanding on January 1 978 2,234 2,705
Exercised (352) (1,252) (464)
Forfeited (32) (4) (7)
Outstanding on December 31 594 978 2,234
Exercisable on December 31 594 978 2,151
Vested and Expected to Vest on December 31 594 978 2,234
Weighted Average Exercise Price [Abstract]      
Outstanding on January 1 $ 14.43 $ 15.78 $ 16.91
Exercised 14.37 16.76 22.15
Forfeited 15.76 38.42 29.99
Outstanding on December 31 14.40 14.43 15.78
Exercisable on December 31 14.40 14.43 15.47
Vested and Expected to Vest on December 31 $ 14.40 $ 14.43 $ 15.78
Weighted Average Remaining Contractual Term [Abstract]      
Outstanding on December 31 2 years 3 months 18 days    
Exercisable on December 31 2 years 3 months 18 days    
Vested and Expected to Vest on December 31 2 years 3 months 18 days    
Aggregate Intrinsic Value [Abstract]      
Exercised $ 16,071 $ 32,096 $ 14,615
Outstanding on December 31 24,261 39,228 77,580
Exercisable on December 31 24,261 39,228 75,372
Vested and Expected to Vest on December 31 $ 24,261 39,228 77,580
Stock Options and SAR's [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Age of Grantee plus Grantees Total Number of Years of Service 70    
Performance Shares [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-Based Compensation Expense $ 6,700 6,000 7,900
Share-Based Compensation Expense, Tax Benefit 2,600 2,300 3,000
Fair Value of Shares Vested During the Period $ 5,500 $ 9,100 $ 7,500
Weighted Average Grant Date Fair Value $ 50.69 $ 43.91  
Awarded - Weighted Average Grant Date Fair Value 63.43    
Forfeited - Weighted Average Grant Date Fair Value 47.10    
Vested - Weighted Average Grant Date Fair Value $ 59.34    
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Outstanding at January 1 91    
Awarded 114    
Forfeited (4)    
Vested (99)    
Outstanding at December 31 102 91  
Unrecognized Compensation Cost $ 2,300    
Unrecognized Compensation Cost, Period for Recognition 1 year 6 months